Chemical fire-extinguisher with expansion device mounted on the discharge-pipe.



W. GRAAFF. CHEMICAL FIRE EXTINGUISHER WITH EXPANSION DEVICE MOUNTED ON THE DISCHARGE PI PE.

APPLICATION FILED JULY 25, 1906.

' Patented May 4, 1909.

'WILHELM GRAAFF, OF BERLIN, GERMANY.

CHEMICAL FIRE-EXTINGUISHER WITH EXPANSION DEVICE MOUNTED DISCHARGE-PIPE.

Specification of Letters Patent.

omens,

Patented May 4:, 1909 Application filed 311131.25, 1906. Serial No. 327,766.

To all whom it may concern:

Be it known that I, WILHELM GRAAFF,

merchant, a subject of the German Emperor, and a resident of Potsdamerstrasse 10-11,

in the city of Berlin, in the Kingdom of Prussia and German Empire, have invented a certain new and useful Chemical Fire-Extinguisher with an Expansion Device Mounted on the Discharge-Pipe, of which the following is a specification.

An inconvenience frequently met with in chemical fire extinguishers, for instance in those of the so-called Minimax-type is the fact, that in view of the necessity of providing a certain air space on top of the liquid constituting the contents of the apparatus, the liquid is very often forced upward into the discharge pipe in the inoperative position of the apparatus on accountof expansion of the inclosed air by heat or by some evolution of gas, such liquid being then capable of escaping to the outside from the discharge ipe by the ejection nozzle. This so-cailled working of the fire extinguisher is particularly to be feared in countries'with. tropical heat, but aside from this, there are other chances of all the causes cooperating together which result in the undesirable discharge of li uid from the nozzle. Various means have een tried, to remedy this difficulty; by making use of boiled or highly heated water for the filling of the apparatus, its property of subsequently evolving gases may be diminished, inasmuch as the gases are thereby made to escape. Another means against this working actlon of the apparatus consists in providing ca illary vent oles on the discharge pipe an( above the level of the. liquid; this remedy is however veig impracticable, because it is impossible to so ,thesedischarge holes from getting choke u after awhile, and furthermore on account 0 the fact that the ejecting pressure and the length of throw of the ejected jet are interferedwith in the employment of the {ii-e1, extinguisher by the blowing oil at these This invention is based on the fact, that the most simple remedy afiorded against these difficulties is, to provide a shoulder or crank shapedpart or an enlai' ement in the discharge pipe above the water evel, whereby an ample collecting space is provided, into which the li uid rising in the discharge pi e, is discharge in the first place, so thatt'e esca e of the liquid from the nozzle is practically excluded. It has however been found, that the arrangement of an intermediate enlarged chamber of this kind directly at the discharge pipe will result in the incon venience, that the force of the ejected jet is considerabl interfered with by this kind of chamber W ich constitutes an interruption of the continuity of the discharge pipe; the V jet, 'which is ejected by the pressure of the carbonic acid actually meeting with a kindof stop 'or resistance in the interior of the discharge pipe'by the liberation of quantitiesof carbonic acid, temporarily evolved in the en'- larged part, so that the jet escapes with a cracking noise and without the desired continuity of the liquid, while at. the same time the length of throw is diminished. In view of this state of facts the present invention is characterized by the fact that a discharge pipe of unaltered continuity is connected with a laterally mounted expansion chamber the interior ofwhich communicates with the interior of the ipe by means of one or two small holes in t e wall of the same and which constitutes a free space for the collection of Up to this height approximatel which will still leave in the upper part of t e apparatus a column of airof, say 25 centimeters, the Minimax-receptacle a is filled with the solution of carbonate of soda. The discharge pipe 6 is arran ed alongside of the receptacle;,it is prefera ly of oval cross-sectiorial shape and extends with a cone-shaped part from the lower and wider entrance openmg up to the ejection nozzle d with an ejection opening turned sidewise. Now, according. to this invention there is provided on the discharge pipe I) at the level AB or above the same, a lateral chamber a which constitutes a kind of collecting s ace for the rising liquid, the communication ein established by small holes a, '0 in thewal of the dis'char 'e pipe. Two holes of this kind, one of whic 1s arranged in the u per and the other in the lower part, are suflicientfor the pur ose. It is essential, that the holes are sma 1, so as to interfere as little as possible vwith the passage of the li uidduring the ,far as the nozzle d, that is to say an escape of the liquid, is excluded.

i What I claim and desire to secure by Let- 5.

ters Patent of the United States is In a fire extinguisher a discharge pipe within the body of the extinguisher, a ho low metal casing laterally secured to the pipe near the level of the extin uishing liquid, a separating wall between tie pipe and said of the pipe,

chamber inline with the wal said wall being provided with apertures to establish communication between the pipe and said chamber, substantially as described.

In witness whereof I have hereunto signed my name this 7th day of July, 1906., in the presence of two subscribing witnesses.

WILHELM .GRAAFF.

Witnesses HENRY HASPER, WOLDEMAR HAUPT. 

